Events | New Diana ISD

When specifying accessible names via `aria-labelledby`, ensure that the 
label elements exist.

## Explanation

Accessible names are required for many parts of a page, including form controls.
One way to accomplish this is to use `aria-labelledby` to specify the ID or IDs of 
other elements which contain a label. For example:

```html
<h2 id="dialog-labell">Important message!</h2>
<dialog aria-labelledby="dialog-label">
```

In this example, the `aria-labelledby` for the `<dialog>` points to an ID of `dialog-label`,
which doesn't exist. The heading it refers to instead has an ID of `dialog-labell`, presumably 
a typo.

## Why this matters

It isn't usually clear when an accessible name is broken, even during user testing.

This check helps to identify where an element clearly intended to have a label, but
that label is missing.

When a label is broken, it may be impossible for a user of assistive technologies
to understand what that element does.

Title / URL	Issues
Events \| New Diana ISDwww.ndisd.org/events?id=48818699	2
Events \| New Diana ISDwww.ndisd.org/events?id=48818738	2
Events \| New Diana ISDwww.ndisd.org/events	2
Events \| New Diana ISDwww.ndisd.org/events?id=48818700	2
Events \| New Diana ISDwww.ndisd.org/events?id=48818719	2
Events \| New Diana ISDwww.ndisd.org/events?id=48694619	2
Events \| New Diana ISDwww.ndisd.org/events?id=48818701	2
Events \| New Diana ISDwww.ndisd.org/events?id=48995445	2
Events \| New Diana ISDwww.ndisd.org/events?id=48994204	2

Fix missing ARIA label IDs

New Diana ISD

Where this issue has occurred